Here's a Family Dog postcard version of a poster from September 22-24, 1967. Artwork is by Robert Fried, and it's listed in the Eric King guide as FD-083-OPC-A.

The headliners for this San Francisco show at the Avalon Ballroom were the Charlatans, with support from Chicago's great Buddy Guy and lights by North American Ibis Alchemical. That same weekend, Donovan played the Cow Palace (he was at the peak of his Mellow Yellow popularity).

As you can see, this card was printed slightly out of register, but my scan is actually worse than the real thing. Very happy with this little gem.